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Rory
Gives Duke Hope
With
the Help of the Rory David Deutsch Foundation's Two Million Dollar Commitment,
Duke Sees a Brighter Tomorrow for Children with Brain Tumors.
The Rory David Deutsch Brain
Tumor Research Program at the Brain Tumor Center of Duke University was
launched last spring to support laboratory and clinical studies in the
area of pediatric brain tumors. With the help of funds from the Rory David
Deutsch Foundation, the program is now undertaking clinical trials of
new chemotherapy treatments that have been found to treat pediatric gliomas
in lab studies. In addition, the world-renowned cancer center is conducting
laboratory research to identify specific genes that may play a role in
tumor growth. The Duke team is also developing vaccines for childhood
gliomas.
Chemotherapy Treatments Show Promise
Two combination chemotherapies
one of Temodar (temozolomide) and CPT11 and another of BCNU and
CPT11 are now being tested on children with brain-stem gliomas.
These clinical trials evolved directly from lab studies conducted at Duke,
which showed that the combination of these agents were particularly synergistic.
Temodar is designed to prevent the replication of rapidly dividing cells,
such as those in tumors. It is the first chemotherapy for this type of
recurrent glioma to come to market in 20 years. Temodar is a methylating
agent that puts a methyl group on a specific part of DNA, which ultimately
leads to cell death. CPT11 has been found in lab studies to enhance the
activity of both Temodar and BCNU. CPT11 is an inhibitor of topoisomerase,
an enzyme that is critical for DNA replication, and is a derivative of
camptothecin, a natural substance found in a tree native to China. BCNU
is an alkylating agent that directly attacks DNA by putting a cross link
between the two strands, resulting in cell death.
Karenitecin is another new chemotherapeutic drug being tested at Duke,
in collaboration with Texas Baylor Hospital. Like CPT11, it is camptothecin-based.
Karenitecin has been observed to have strong antitumor activity at low
concentrations and is designed to have less toxicity and drug resistance
than other camptothecins. Unlike typical water-soluble camptothecins,
Karenitecin is fat soluble, which scientists believe may give it enhanced
power to penetrate tissue.
These studies represent a portion of the substantial research and clinical
trials on brain tumors that are taking place at Duke. The Rory David Deutsch
Foundation recently made a research grant in the amount of $2 million
to be paid over ten years, ensuring the perpetuity of this program. This
is enabling the Duke Brain Tumor Center to explore new approaches against
childhood gliomas that would not be possible without the Foundation's
support.
New
Molecular Targets Identified
Duke is also identifying
a vast number of the genes found in a given type of brain tumor. Researchers
are looking to see what genes are present in gliomas that are not found
in healthy brain cells. If a gene is unique to a brain tumor, it is being
targeted for diagnostic purposes and the development of treatment therapies.
Vaccines on the Horizon
In recent years
many growth factor molecules for specific cells in the body's immune system
have been identified. Methods for growing antigen-presenting cells (an
antigen is a substance that produces an immune response) called dendritic
cells have been developed. As a result of this progress, many vaccine
trials for different types of cancer are being undertaken. For example,
Duke researchers have been able to culture and expand dendritic cells
from brain tumor patients. These dendritic cells are being exposed in
test tubes in the laboratory to a large number of gene products from childhood
gliomas. These cells are then analyzed for their ability to activate immune
cells. Once dendritic cells have been pulsed with specific tumor-related
gene products from childhood gliomas and have been shown to activate immune
cells, these pulsed dendritic cells can be reintroduced into patients
with brain tumors. These clinical trials will allow determination of the
safety and effectiveness of these vaccines. Vaccine and immune approaches
are particularly promising, since they carry much less toxicity to the
normal brain than existing treatments of chemotherapy and radiation therapy.
"Because of the Foundation's support and general advances taking
place in cancer biology, I feel confident that within my lifetime effective
treatment of childhood gliomas will become a reality," says Dr. Darell
Bigner, leader of the Neuro-Oncology Program and deputy director of the
Duke Comprehensive Cancer Center.
"With the help of the Foundation, we can accelerate our progress
and move closer to successfully treating and ultimately finding a cure
for this disease," explains Dr. Henry Friedman, co-director of the
Clinical Neuro-Oncology Program at the Brain Tumor Center.
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